System for changing the fuel supply



Aug. 27, 1968 E. SENN 3,398,816

SYSTEM FOR CHANGING THE FUEL SUPPLY Filed March 14, 1966 5 Sheets-Sheet l E. SENN 3,398,816

5 Sheets-Sheet 2 SYSTEM FOR CHANGING THE FUEL SUPPLY Q H m m 2* i1 0 WW m N m J mm mm 1 n" om H x i o 69 fin fim mu m N Q K 2 l. FIT. w u 1....l mum MN I x w mm E mm m M %& m n .i mm Sm h m II g m i 3 U a v m QQ Aug. 27, 1968 Filed March 14. 1966 Aug. 27, 1968 Y I E. 'SENN 3,398,816

SYSTEM FOR CHANGING THE FUEL SUPPLY Filed March 14, 1966 5 Sheets-Sheet} Aug. 27, 1968 E SENN SYSTEM FOR CHANGING THE FUEL SUPPLY 5 Sheets-Sheet 4 Filed March 1-1, 1965 Aug. 27, 1968 Filed March 14, 19%

E. SENN SYSTEM FOR CHANGING THE FUEL SUPPLY 5 Sheets-Sheet 5 United States Patent 3,398,816 SYSTEM FOR CHANGING THE FUEL SUPPLY Eduard Senn, Hungerburg 46,

Innsbruck, Tyrol, Austria Filed Mar. 14, 1966, Ser. No. 534,027 Claims priority, application Austria, Mar. 15, 1965, A 2,292/65; Oct. 21, 1965, A 9,548/65 27 Claims. (Cl. 192-.9)

ABSTRACT OF THE DISCLOSURE A system for changing the fuel supply to an engine for a motor vehicle in which an accelerator lever and a positioning means cooperable with a control element for controlling the fuel supply to the engine is provided with, the accelerator lever and the positioning means being coupled mechanically to the control element. The positioning means is adapted by way of a switch operable by the driver for adjusting the control element to control the fuel supply to the engine alternatively to increase or decrease the fuel supply when the accelerator lever is released.

This invention relates to system for changing the fuel supply to an engine of the internal combustion engine t e.

in known systems for changing the fuel supply to engines in motor vehicles, a positioning motor is provided in addition to the acelerator lever and cooperates with the control element for controling the fuel supply to the engine. In the known systems, the positioning motor consists of an electric motor, which is fed from a DC. source. The positioning motor has two armature windings. One of said armature windings serves for a righthand movement and the other for a left-hand movement. Each of the armature windings is connected to a contact, and a cooperating contact is provided, which is connected to one pole of the source of current for energizing the positioning motor and adapted to selectively contact one or the other of the contacts which are connected to the armature windings. The two contacts connected to the armature windings are secured to a fork, which is movable by a speed governor. The cooperating contact is connected tothe accelerator lever and movable between the armature winding contacts, which act as stops. When in the operation of the known system the foot is lifted off the accelerator lever, the cooperating contact will get into touch with the contact of that armature winding which is energizalble for a rotation of the electric motor in a direction in which the control element for controlling the fuel supply to the engine is moved toward the no-load position. Thus, the known apparatus does not enable a driving of the vehicle unless the foot is on the accelerator lever. This is a disadvantage because the action of the foot on the accelerator lever results in fatigue of the driver on superhighways or well-designed long-distance highways.

Hence, it is an object of the invention to provide a system which enables a driving of the vehicle even without an action of the foot on the accelerator lever and which nevertheless enables at any time a sensitive change of the driving speed.

Another object of the invention is to provide a system which enables a maintenance of any desired, selected driving speed as well as an increase or decrease of said speed at any time without an operation of the accelerator lever.

A further invention is to provide a system in which a disengagement of the clutch or an application of the brake causes a movement of the control element for 3,398,816 Patented Aug. 27, 1968 ice controlling the fuel supply to the engine to its no-load position.

These objects are accomplished in a system for changing the fuel supply to engines of motor vehicles, which apparatus comprises an accelerator lever anda positioning motor, which cooperates with the control element for controlling the fuel supply to the engine, the accelerator lever and the positioning motor being mechanically coupled to the control element for controling the fuel supply to the engine, the control element for controlling the fuel supply to the engine being adjustable in the sense of a higher and lower fuel supply rate by a switch, which is operable by the driver when the accelerator lever is relieved.

Further objects and advantages of the invention will become apparent from the following specification in conjunction with drawing.

FIG. 1 is a diagrammatic view shown the system according to the invention with the electrical connections.

FIG. 2 is an electric circuit diagram of a system shown in FIG. 1.

FIG. 3 shows a modification of FIG. 1.

FIG. 4 shows as in detail a modification of FIGS. 1 and 3.

FIG. 5 is an electric circuit diagram of a system as shown in FIG. 3

FIG. 6 shows a modification of FIGS. 1 and 2.

In the drawing, a control element 1 is provided for controlling the fuel supply to the engine 270. In the embodiment shown by way of example, the control element 1 is a carburetor, which is supplied with air by a funnel 36 and with fuel by a conduit 37. The fuel-air mixture is supplied through an intake conduit 38 to an engine 270. The control element 1 is adjusted by means of a rocker lever 10, which is connected to shaft 39 of a butterfly valve (not shown), which is incorporated in the carburetor 1. The control element 1 may alternatively consist of a fuel injection pump. A rocker lever 1a is connected by a two-armed lever 3 and a cable 4 to one arm 5a of an accelerator lever 5, which consists of a bell-crank lever and is pivoted on a stationary shaft 6, which is secured e.g., to a splash wall 40. The two-armed lever 3 is pivoted on a shaft 3a, which is secured in a bearing block 41, which is secured by screws 42 to a rib 43 of the engine 270.

The cable 9 extends around a deflecting roller 10, which is rotatably mounted in a housing 10a, which is secured to the engine 270. The cable is secured to a winding drum 11, shaft 44 of which is rot-atably mounted in a bearing 45, which is secured to the engine 270. The drum 11 is driven by a positioning motor 15, which in the embodiment shown by way of example consists of an electric motor. Instead of an electric motor, another motor, e.g., a hydraulic motor or a pneumatic motor or a motor which operates in dependence on the intake pressure may be used. A speed-reducing transmission 46 and a clutch 12 are interconnected between the drum 11 and the position ing motor 15. A disc 47 of clutch 12 is urged by a spring 12a against the drum 11 and may be disengaged from the drum 11 against the action of the spring 12a by the operation of an uncoupling lever. An uncoupling lever 19 is connected by a spring 18 to a pedal 16, which is pivoted about a bearing 17, which is secured to the splash wall 40. When the pedal 16 is pivoted in the direction of the arrow 16a by the foot of the driver, the clutch between the drum 11 and the positioning motor 15 will be disengaged. The pedal 16 is connected by a linkage 4'8, 49 to the clutch of the motor vehicle, which in the embodiment shown by way of example is accommodated together with the transmission in a housing 50. A drive shaft 51 of the motor vehicle extends from the housing 50. The engine 270, the housing 50 and the splash wall 40 are secured to frame 52 of the motor vehicle. This frame carries the wheels of the motor vehicle. Of these wheels, only one front wheel 53 is shown.

The pedal 16 may also serve for actuating the brake. When the accelerator lever is moved in the direction of the arrow 8a, e.g., by the foot of the driver, this movement will be transmitted by the cable 4, the two-armed lever 3 and the cable 9 to the rocker lever 1a of the control element 1, which controls the fuel supply to the engine. In this case, the rocker lever 1a is moved in the clockwise direction in the drawing against the force of a return spring 2, which tends to move the rocker lever in to a position which corresponds to the no-load condition of the engine. This position is defined by the engagement of the accelerator lever 5 with an adjustable stop 7, which is secured to the splash wall 40.

When the clutch 12 is engaged, the lever pivotally moved by the positioning motor 15 by means of a speed-reducing transmission consisting of a worm 14 and a worm wheel 13. Depending on the direction of rotation of the positioning motor 15, the cable 9 will be wound up on the drum 11 or unwound therefrom. The engine will be accelerated when the cable 9 is being wound up on the drum 11 and will be decelerated when the cable 9 is being unwound.

The energization of the positioning motor controlled by a switch 220, which is operable by the driver. For this reason, the foot can be taken from the accelerator lever 5 and the speed of the vehicle can be increased or reduced as desired by means of the switch 220. The switch 220 may be moved to a position which is indicated in FIG. 1 so that the positioning motor is energized for a rotation in that direction in which it tends to wind up the cable 9 on the cable drum. When the switch 220 is moved by the driver from the position marked 0 to the position marked the positioning motor will be driven in a direction in which it tends to unwind the cable 9 from the drum 11 and the fuel supply to the engine 270 is reduced.

The device for controlling the direction of rotation of the positioning motor 15 is accommodated in a housing 54, which is secured to the splash wall 40. The wiring of the elements accommodated in this component is apparent from FIG. 2 and will be described more fully hereinafter with reference to FIG. 2.

Instead of controlling the positioning motor 15 by hand by means of the switch 220, any desired driving speed may be selected and this selected speed may be maintained by a controller 55. The speed is selected by an operation of the setting knob 56 when a switch R accommodated in a housing 61 has been operated to render the controller operative. The desired speed is determined by the setting of the setting knob 56. A signal which is representative of the actual speed is transmitted by actual value signal generator 26, which in the embodiment shown by way of example consists of a tachometric electric generator and is driven through a chain drive 57, 58, 59 from crankshaft 60 of the engine 270. The actual value signal generator may alternatively detect the ignition frequency and transmit a signal representative of this frequency to the controller 55. Depending on the sign (positive or negative) of the difference between the actual value and the desired value, the positioning motor will be energized for a rotation in the clockwise or counterclockwire direction. A spring 18a, which is relaxed during normal operation, is connected by a cable 18b to the setting knob 56. By means of this spring 18a, the uncoupling lever 19 for the clutch 12 between the drum 11 and the positioning motor 15 acts on the setting knob 56 so that an operation of the pedal 16 will result in a return movement of the setting knob 56.

The drum 11 has a contact finger 62 secured thereto which in the no-load position operates two limit switches 32a and 32b and in the full-load position when the cable It: may be 15 may be 9 is fully wound up, operates a limit switch 31. The mode of operation of limit switches 32a, 32b and 31 will be explained more fully with reference to FIG. 2, as will the function of actual value signal generator 26, which is connected by leads 63, 64 to the controller 55.

In FIG. 2, control housing 54, switch housing 61 and controller 66 are shown on a larger scale than in FIG. 1 so that details of the electrical circuitry become apparent. The limit switches 31, 32a and 32b are shown as though they were accommodated in the controller 55 and the control housing 54, respectively.

The terminals of the positioning motor, which is a DC.- motor, are indicated at a, 15b, 15c. The terminal 15a is permanently connected to one pole of a battery 33. When the terminal 15b is connected by a contact to the other pole of the battery, the motor will rotate, e.g., in clockwise direction. When the terminal 150 is connected by a contact 21 and a fuse to the other pole of the battery, the motor 15 will rotate in the counterclockwise direction. The contacts 20 and 21 are operated by relays or contactors 20a and 21a, which can be alternatively included in the circuit by a change-over switch A. In the case of a manual control, the change-over switch A is operated by switch 220, which is controlled by the driver.

When it is desired to use the controller in order to maintain the vehicle at a constant speed, the change-over switch A must automatically energize relay 20a or relay 21a when the actual speed is higher or lower than the selected speed. The motor 15 will then be energized alternatively through the terminal 15b or 150. In one case, the cable 9 will be unwound from the drum 11. In the other case it will be wound up on said drum. When the switch R has been manipulated to render the controller operative, the change-over switch A is operated by two coils 22a and 22b, which are energized in dependence on the sign of the difference between the actual speed and the desired speed.

In the embodiment shown by way of example, the desired value signal generator consists of a potentiometer 25 having a slide tap 25a. The voltage tapped from the potentiometer 25 corresponds to the desired driving speed. The voltage tapped from the potentiometer is compared with the voltage which is applied from tachometric generator 26 by terminals and 101 to the controller. The output voltage of the tachometric generator 26 depends on the speed of crankshaft 60. This output voltage is an A.C. voltage and is rectified in a rectifier 27. The circuit is designed so that there is no current flow through coils 22a and 22b when the output current of the actual value signal generator 26 and the output current of the desired value signal generator or potentiometer 25 have the same value. In this case, the change-over switch A remains in its intermediate position. The change-over switch A may consist, e.g., of an armature of a polarized relay. In the case assumed above, the windings of relays 21a and 20a will remain deenergized so that switches 21 and 20 for reversing the motor 15 will remain open and this motor remains deenergized. When the output current of the desired value signal generator 25 is higher, a current will flow through a rectifier 23 and the coil 220 so that the change-over switch A moves to the left, with the relay 21a being energized and the contact 21 closed. The motor 15 rotates in such a direction that the control lever 1a is moved to a position corresponding to a higher driving speed. If the output current of the actual value signal generator 26, corresponding to the actual value, is higher, a current will flow through a rectifier 24 and the coil 22b so that the change-over switch 22 is moved to the right, the coil 20a is energized and the contact 20 closed. The motor 15 begins to rotate in the opposite direction and moves the control lever 1a to a position which corresponds to a lower speed. Thus, the potentiometer can be set to any desired driving speed which the engine is capable to maintain.

Some additional relations will now be explained with reference to FIGS. 1 and 2. When the foot operates the pedal 16, the slide tap 25a of the desired value signal generator is moved to a zero position by means of the spring 18a. The slide tap 25a is now in contact with the vacant contact 25b so that the current which is representative of the desired value is zero. The current which is representative of the actual value is now higher and the motor 15 is restored to zero. In the no-load position, limit switches 32a and 3211 are operated so that the contacts 32a and 32b are opened, the motor deenergized and no current which is representative of the actual value can flow through coil 22b. Only when the slide tap of the desired value signal generator is moved away from contact 25b can the operation of the controller be resumed. As has already been described hereinbefore, an operation of the pedal 16 causes a disengaging of clutch 12 so that the spring 2 moves the drum to its zero position. The limit switch 32 deenergizes the motor even if the change-over switch 20 was still closed by the current flowing from the desired value signal generator through coil 22b. Such a current cannot flow, however, because the contacts 32a and 32b are open.

It may be assumed in FIG. 1 that the control lever 1a has just moved somewhat beyond the position which corresponds to the maximum fuel supply rate to the engine. The limit switch 31 is then operated by contact finger 62 mounted on the drum 11 and the contact 31 is opened. The current which is representative of the desired value is thus reduced to zero and the current which is representative of the actual value causes the motor 15 to moveto its zero position. This action indicates to the driver that the setting element has been moved slightly beyond the end point and a further increase of the desired value will not result in an increase in speed as the power rating of the engine has been exceeded. Numerals 28 and 29 designate adjusting resistors. In this case, the driver must select the next lower speed unless he has already recognized the need for doing so before from the behaviour of the engine.

A signal causing a selection of a lower speed may be derived from the described position of the controller (slightly in excess of the maximum fuel supply rate) if the engine is provided with an automatic transmission. To enable a starting of the engine when the drum 11 is in its zero position, a push-button switch having contacts 35a and 35b is operated -by hand after the desired value signal generator has been set to a value which slightly exceeds the actual speed value.

In the embodiment shown by way of example in FIG. 3, like reference characters designate the same parts as in FIGS. 1 and 2. These parts will not be described in connection with FIG. 3.

For a clearer showing, the drum 11, which is firmly mounted on the engine, the clutch 12 and the positioning means e.g. a positioning motor 15 with worm 14 and worm wheel 13 are illustrated in an exploded view. The clutch 12 and the positioning motor 15 with the worm 14 and the worm wheel 13 are preferably fixed on the motor 270. The rocker lever 1a of the control element 1 for controlling the fuel supply to the engine may be adjusted by an accelerator lever 5, a linkage 4a, a bellcrank lever 3, and a cable or linkage 4 and may also be moved by the positioning motor 15. This positioning motor drives by means of the locking means, e.g., a selflocking worm gearing 13, 14 and the clutch 1'2, and the drum 11 on which the cable can be wound and from which it can be unwound. The cable extends around a deflecting roller and is connected to the linkage 4a or the bell-crank lever 3 by a cable 65. Thus, the control lever 1a of the control element may also be operated by the cable 9 when the accelerator lever 5 is not held by the foot. The cable 9 is further connected to a spring 70 which is secured to the engine 270 and tensions the cable and tends to unwind the cable 9 from the drum. The control lever 1a is connected to a spring 2 which is secured to the engine 270 and tends to move the control element to its no-load position.

Different from the embodiment shown in FIG. 1, the clutch 12 comprises a gear 12c which is rotatably mounted on a rocker 200 and meshes both with a gear 12b and with a gear 12d. The gear 12d is adapted to be driven by the worm gearing 13, 14. The gear 12a serves for driving the cable drum 11. During normal operation, the rocker 200 is held by a latch 19, which is pivoted in a stationary bearing 19a and is moved by a spring 18 to a position in which the latch interengages with the rocker 20 and locks the same. An operation of the brake or of the clutch pedal 16 causes a pivotal movement of the latch 19 against the force of spring 18 so that the rocker 200 is released, with the spring causing an unwinding of the cable 9 from th drum 11 and the return spring 2 returns the control element 1 to its no-load position. When cable 9 is being unwound from the drum 11, the gear 12d which is connected to the drum 11 is rotated and the rocker 200 is lifted by the tooth pressure acting on the gear which is mounted on the rocker 200. The lifting of the rocker 200 causes the gear 12c to disengage the gear 12b which is connected to the worm gearing 13, 14. The latch 19 may alternatively be disengaged by a solenoid Ma, by hydraulic means, or by compressed air which is produced with the aid of the intake pressure. The clutch is disengaged after an actuation of switches Br and Kit which are engaged by stops 67 and 68 of the clutch linkage 48 and of the brake linkage 69, respectively when the brake pedal 66 or the clutch pedal 16 are operated. A pull rod 69 of the brake linkage is connected to a two-armed lever 71 which is pivoted to a frame 52 of the vehicle and to which cable 71' is secured. A cam-like contact finger 62 is secured to the drum. In the no-load position, this finger operates a limit switch 2 In the full-load position, this finger operates a limit switch e The action of switches 2 and e will be explained more in detail with reference to FIG. 5.

As in FIG. 1, the control of the positioning motor 15 is accommodated in a control housing 54. A rocker lever 220 is operable to energize the motor for rotation in opposite directions. In one position, the rocker lever 220 acts on a pressure-response switch 1a for a deceleration and in the other position on a pressure-responsive switch sch which causes an energization of the positioning motor for a rotation in a direction in which it tends to wind up the cable 9 on the drum 11. The signal lights I1 and h.; are provided to indicate whether the positioning motor 15 is operating to increase or decrease the fuel supply to the engine 270.

The embodiment shown in FIG. 3 also is used to maintain any selected speed. A controller 55 is used for this purpose and may be analogous in design to that shown in FIG. 2. The signal which is representative of the desired speed may be supplied from a desired value signal generator consisting of a tachometric generator 26. The controller may be rendered operative by an actuation of a switch R. A signal light h indicates that the controller is in operation whereas a signal light h, indicates that the manual control is effective.

FIG. 4 shows diagrammatically how the function of drum 11 can be alternatively accomplished with the aid of a piston 210 which is slidably mounted in a cylinder 230. Like elements in FIGS. 3 and 4 are provided with like reference characters.

As in FIG. 3, the accelerator lever 5 is mounted in the frame 52 of the vehicle. The two-armed lever 3 and the control lever 1a are pivoted to the engine 270. It is apparent from FIG. 4 that a tensile element 9 is linked to the piston and connected to the two-armed lever 3 so that the control lever In for controlling the fuel supply to the engine 270 is operable by the cable or linkage 4. The cylinder 230 may be supplied with a pressure fluid, e.g., by means of valves 231, 232. The valves 231, 232

may be controlled by the positioning motor 15, e.g., by means of an eccentric and a rocker arm.

The circuitry shown in FIG. 5 is accommodated in the control housing 54, the switch housing 61 in FIG. 3 and has the following mode of operation. The controller 55 is analogous in design to that of FIG. 2 and its action on the change-over switch A in FIG. 5 is analogous to that of FIG. 2. For the sake of a clearer showing, the coils 22a and 22b for operating the change-over switch have been omitted in FIG. 5. In the circuit diagram of FIG. 5, the positioning motor is connected to terminals 103 and 104. The motor 15 consists of a constant-field DC. motor which can be reversed by reversing the polarity of the armature terminals.

The relays and their associated contacts are identified by letters a to e in FIG. 5. The rocker 226 has pressure responsive switches sch (faster) and la (slower) for conmeeting the positioning motor 15 to the battery B for rotation in a direction to increase and decrease the fuel supply rate, respectively. When pressure is applied to the pressure-responsive switch sch, relay c is energized through contact sch and the decelerating circuit from the change over switch A, which is controlled by the output of the controller, is interrupted by the switch sch and subsequently by the switch c,.

When pressure is applied to la, relay d is energized through la and the accelerating circuit from the changeover switch A, which is controlled by the output of the controller, is interrupted by the switch la and subsequently by the switch a',. The switches 0 and d are included in the circuits which are associated with the op posite relays d and c. The change-over switch A can assume a. neutral position and is controlled by the output signals of a controller, as has already been mentioned. The controller establishes higher fuel supply rate when the desired value is higher and a lower fuel supply rate when the actual value is higher, as has been explained with reference to FIG. 2. Instead of a tachometric generator, the means for supplying the desired value signal to the controller may consist of a device which generates signals in response to the frequency of the ignition magneto or, in diesel engines, of a device which is synchronized with the speed of the engine.

In the following specification, the controller and the switch A, which is controlled by the controller, will be left out of consideration.

When the pressure-response switch sch is actuated, the relay 0 opens the switch to interrupt the decelerating circuit. The sense-controlling switches 0 and c connect the positioning motor to the battery B. The battery voltage will not be applied until the relay b has been energized to close the switch b in the circuit which serves for energizing the positioning motor 15. The relay b is selfholding by a switch b which is adapted to be closed by a starting switch H, which is manually operable by a push button.

When the foot brake pedal and/or the clutch pedal is depressed for a short time, a switch Br or Ku is closed to energize a relay a so that the switch a is closed to energize the release solenoid Ma for operating the latch 19 for rocker 200. At the same time, the reversal of switch a deenergizes the relay b which is a slow-releasing relay so that the contact b which is associated with the relay b and included in the circuit leading to relay :1 does not open too soon. Such a premature opening would return a to its previous position so that the solenoid Ma would be deenergized. Owing to the slow release characteristics of relay b, there is suflicient time for the operation of the solenoid Ma to release the rocker 200 and consequently the clutch 12.

When it is desired to use the controller, a controller start switch R is operated by its push button to energize a relay e which is self-holding by the contact e which has been operated by the controller start switch R. Therelay e operates a switch e which applies voltage to the switch A controlled by the output of the controller. An overriding of the action of the controller is enabled at any time by the pressure-responsive switches la and sch of the preselector 220.

The circuits which lead to the control relays c, d of the direction-controlling switches 0 c and d d incorporate interrupters E and E respectively, which are operated by limit switches e e or e e associated with the no-load position and the full-load position of the control element 1 for controlling the fuel supply to the engine. Said limit switches for the no-load and full-load positions of the control element 1 are controlled by a control cam 24 mounted on the drum 11 and/or by an arm 250 which is connected by the linkage 4 to the accelerator lever 5.

To facilitate a location of a fault, the leads which extend to the individual relays a, b, c, d, e and to the motor 15 are protected by fuses s to s Signal lights h to 11 are provided to indicate that the system is ready for manual operation (h or for controller operation (k as well as to indicatethat the positioning motor is moving to increase (k or decrease (h.,) the fuel supply.

One pole of each of the contacts of the release solenoid Ma and of the interrupters E and E may be grounded so that a single insulated supply lead is sufiicient.

The positioning motor may consist of a hydraulic motor or a motor which is supplied with compressed air or operates in response to the intake pressure.

The use of the present system enables a uniform operation of the control element so that much less fuel is consumed than during pedal control.

It is also important that there is no relative movement between the positioning motor, or a loading element which is incorporated in the linkage for adjusting the control element on the one hand, and the control element for controlling the fuel supply to the engine on the other hand. It will be particularly desirable if the positioning motor is secured to the engine block together with the control element for controlling the fuel supply to the engine. This control element is usually secured to the engine block. The positioning motor may be of any desired type, e.g., one of the types indicated above. It will be preferable, however, to use an electric positioning motor which may be controlled in the manner which has been described hereinbefore.

FIG. 6 shows a development of the invention. The linkage leading to the control element 1 incorporates a locking element, which, in the embodiment shown by way of example,'consists of a ratchet wheel 26 held by the latch 19 against a rotation in one rotation. The release of the latch 19 is analogous to the release of the latch 19 in the embodiment shown in FIG. 3. In order to avoid a dislocation of the locking member relative to the control element 1, the locking member (ratchet wheel 26) and the control element '1 are mounted on the same inherently rigid body, such as the engine block 270. This arrangement ensures a perfectly rigid transmission of movement.

When a speed reduction without a setting to the noload position is desired in the system shown in FIG. 6, the accelerator lever is held by the foot and the clutch or brake pedal is depressed for a short time by the other foot. The setting knob 28 for manual operation will now return to its zero position but this knob can then be turned in a speed-increasing direction until the accelerator lever 5 is held in its position.

Instead of means for a mechanical operation by hand, i

a manually controlled positioning motor or a controller may be used to operate the system shown in FIG. 6. A manual overriding of the controller action may also be provided for. These features may be similar to the embodiments described hereinbefore so that a detailed explanation is not required here.

FIG. 6 shows in dotted lines the limit switches e 9 and e which cooperate with the accelerator lever 5 and its linkage 4a. These dotted lines indicate that said switches are not always required. The same remark applies to the gear 12d to indicate that in the embodiment shown in FIG. 6 a clutch of the type shown in FIG. 3 may be used together with a positioning motor 15.

Within the scope of the present invention it is also possible to provide a lever for an automatic transmission (in most cases a lever like the former accelerator lever) and this lever may be locked in position because the automatic transmission will 'be firmly connected to the engine block in almost all cases and the lever can be locked in position relative to the engine block so that the irregularities and shakes which were previously produced by the drive-rs foot avoided and fuel can be saved.

Within the scope of the invention it is also possible to locate the ratchet wheel 26 on the axis of the control element 1 or on the axis of the rocker lever 1a whereby it is possible to eliminate the setting knob 28 and the bar leading to this knob.

The cable 9, the deflecting roller and the spring means 7 also can be eliminated when the ratchet wheel 26 is fixedly mounted on the axis of the control element 1. If it is not possible to locate the ratchet wheel 26 on the axis of the control element 1 it is also possible to mount said ratchet wheel on the axis 30 of the two-armed lever 3.

While there has been shown and described a particular embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is aimed to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as my invention is:

1. A system for changing the fuel supply to an engine in a motor vehicle, comprising a control element, an accelerator lever and a positioning means which cooperates with the control element for controlling the fuel supply to the engine, the accelerator lever and the positioning means being mechanically coupled to the control element for controlling the fuel supply to the engine, a switch operable by the driver, the positioning means being adapted, under control of the switch to adjust the control element for controlling the fuel supply to the engine alternatively to increase or decrease said fuel supply when the accelerator lever is released, and said positioning means being an electric motor and reversible by a change-over switch operated by a selected one of two relays which are energizable by a preselector switch.

2. The system as set forth in claim 1, in which the preselector switch is adjusted by two adjusting elements, which act in opposite directions on the preselector switch and are connected parallel to each other and in series with rectifiers in a control circuit which is fed by an adjustable potentiometer and by a source of current having a voltage or current value of which depends on the speed of the engine so that either of the adjusting elements is energized in response to the difference between the voltage across the potentiometer, which voltage is representa tive of the desired speed value, and the output yoltage of the speed-responsive source of current, which output voltage is representative of the desired value.

3. The system as set forth in claim 2, in which the adjustable potentiometer is fed by the source of current for energizing the positioning motor.

:4. The system as set forth in claim 2, in which the two adjusting elements for operating the preselector switch are separable from the control circuit by a cut-off switch which is arranged to be operated when the control element for controlling the fuel supply to the engine reaches its no-load position, and a switch being arranged to deenergize the positioning motor at the same time.

5. The system as set forth in claim 2, in which the voltage tapped from the potentiometer and which voltage is representative of the desired value and applied to the 10 control circuit, is adapted to be reduced to zero by the opening of a switch which is connected between the potentiometer and the adjusting elements for the preselector switch.

6. The system as set forth in claim 5, in which said reduction of the voltage tapped from the potentiometer to zero results in a command for changing the transmission to the next lower speed.

7. The system as set forth in claim 2, in which an operation of the brake or pedal disengages a clutch which is connected between the positioning motor and the control element for controlling the fuel supply to the engine, and which causes a spring to move the control element to its no-load position.

8. The system as set forth in claim 7, in which said operation of the brake or clutch pedal causes a reduction to zero of the voltage which is tapped from the potentiometer and applied to the control circuit and which is representative of the desired speed value.

9. The system as set forth in claim 1 in which said preselector switch comprises two selectively operable, pressure-responsive switches, each of which has a control relay associated therewith and is operable to close the circuit of said relay and at the same time interrupt a circuit which extends from the respective other control relay and adapted to have a voltage applied thereto by a switch which is controllable by the output of a controller.

10. The system as set forth in claim 9, in which said pressure-responsive switches are operable by a rocker which is arranged adjacent to the steering wheel.

11. The system as set forth in claim 9, in which a cutofi switch is connected in series with the switch that is controlled by the output of the controller and said cutoff switch being controllable by a self-holding relay which is energizable by an operation of a push button.

12. The system as set forth in claim 9, in which the operation of the brake pedal or clutch pedal causes an actuation of either of two switches, and said actuation of said switch energizes a relay which is operative to move a switch from its initial position to close the exciting circuit of a coil which is operative to disengage a clutch connected between the positioning motor and the control element for controlling the fuel supply to the engine.

13. The system as set forth in claim 12, in which the operation of the switch which closes the circuit of the coil interrupts a circuit of a slow-releasing relay, the release of which causes an opening of a switch in the circuit of the coil relay so that the latter is released and the switch controlling the energization of the coil returns to its initial position.

14. The system as set forth in claim 13, in which the switch for controlling the energization of the coil connects in its initial position the source of current to the circuit which leads to the pressure-responsive switches of the preselector switch for controlling the direction of rotation of the positioning motor and said circuit includes a switch which is adapted to be short-circuited by a push-button operable switch, which in closed position, causes the energization of the slow-releasing relay, operative to close a switch included in the circuit of the positioning motor.

15. The system as set forth in claim 13, in which interrupters are included in the circuits of the relays for controlling the reversing change-over switch.

16. The system as set forth in claim 15, in which said interrupters consist of contacts of limit switches which are arranged to be operated when said control element for controlling the fuel supply to the engine is in its no-load position and full-load positions, respectively.

17. The system as set forth in claim 16, in which said limit switches arranged to be operated when said control element in its no-load and full-load positions, respectively, are operated by a drum on which a cable for operating the control element is adapted to be wound.

18. The system as set forth in claim 16, in which said limit switches arranged to be operated when said con- 1 1 trol element is in its no-load and full-load positions, respectively, are operated by linkage for operating the control element.

19. The system as set forth in claim 17, in which said drum is returned by an additional spring even when the accelerator lever is spaced from its no-load position.

20. The system as set forth in claim 9, in which said positioning motor has a field which is established by a permanent magnet and the direction of rotation is changed by reversing the polarity of the armature.

21.The system as set forth in claim 9, in which said positioning motor controls an automatic control lever of an automatic transmission.

22. The system for changing the fuel supply to an engine in a motor vehicle, comprising a control element for controlling the fuel supply to the engine, an accelerator lever and a positioning means which cooperates with the control element and is mounted so as to be nondisplaceable relative to the control element for controlling the fuel supply to the engine.

23. The system as set forth in claim 22, in which said positioning means is a motor and said control element for controlling the fuel supply to the engine and said motor are mounted on the engine block.

24. The system as set forth in claim 22, in which the positioning means comprises a latching means with said latching means being mounted so as to be non-displaceable relative to the control element for controlling the fuel supply to the engine. 1

25. The system as set forth in claim 22, in which the positioning means comprises a latching means with said latching means being disengageable by a solenoid.

26. The system as set forth in claim 22, wherein the positioning means comprises a latching means, with said latching means being disengageable by hydraulic means.

27. The system as set forth in claim 22, wherein the positioning means comprises a latching means, with said latching means being disengageable by compressed air, which is produced with the air of the intake pressure.'

References Cited UNITED STATES PATENTS 2,631,700 3/1953 Long et a1 l92-.09 2,987,054 6/1961 Eddy 1923 X FRED C. MATTERN, J R., Primary Examiner. ARTHUR T. MCKEON, Assistant Examiner. 

